CONTROL OF INSECTS ATTACKING STORED TOBACCO 



29 



Figure 21. — Fifty-gallon wooden barrel and other apparatus used with sodium cyanide for 

 generating hydrocyanic acid gas. The man, equipped with a gas mask, is resting the bag 

 of sodium cyanide on the edge of the barrel before lowering it carefully into the acid- 

 water mixture. 



several feet of soil or dumped into sewer drains when these prac- 

 tices do not conflict with public health regulations. This residue 

 should not be dumped indiscriminately, and a permit should be 

 obtained from the proper public health authorities for disposing 

 of it. 



